This invention concerns the incorporation of a high pressure venting mechanism into a firearm to prevent injuries to the firer in the event of a chamber explosion. This invention is especially suitable for a rifle of the xe2x80x9cbull-pupxe2x80x9d type where the barrel/ receiver is mounted in the bullstock.
In the typical firing cycle of a firearm, a chamber explosion may occur if there is a projectile stuck in the barrel bore and a defective round is fired. The effect of the chamber explosion will not only cause damage to the weapon, but will also cause injuries to the firer from the fragmentation of the rifle and the hot high-pressure gases produced as a result of the explosion.
This danger is particularly acute for the xe2x80x9cbull-pupxe2x80x9d type rifle, where the barrel/receiver assembly is mounted in the upper-receiver. The benefit of a bull-pup rifle is that the overall length of the rifle is shorter than other rifle types. However, the rifle is such that the magazine holder and firing chamber is behind the trigger mechanism. As a result, the location of the firing chamber is adjacent to the face of the firer when the firer is taking aim. When a right-handed firer is using his weapon to aim at the target, he will naturally rest his face on the left side of the weapon receiver body. Since the firer""s face is adjacent to the firing chamber during firing, the extent and risk of injury to the firer is greater than for other types of rifles. To protect the firer""s face in the event of a chamber explosion, the left receiver body must remain intact under the impact of a chamber explosion.
The receiver body is typically made of plastics material. In order to prevent fragmentation of the rifle in the event of a chamber explosion, the receiver body could be made of stronger material, such as metal, but that would increase the overall weight of the rifle and reduce the ease of use.
The aim of this invention is to ensure that there are no fragments hitting or hot gases burning a firer""s face if the receiver body of the firearm breaks up into pieces due to high pressure gas acting on it in the event of a firing chamber explosion. Another aim of this invention is to minimise damage to the firearm in the event of a chamber explosion while at the same time using light-weight material for the receiver body to reduce the overall weight of the rifle.
Accordingly the present invention provides a firearm for discharging a high velocity projectile, the firearm comprising a body having a barrel communicating with a chamber for receiving the projectile and a firing mechanism for initiating projectile discharge, characterised in that the body has high pressure relief means disposed, in normal use, remotely from the firearm user for venting high pressure gases produced by a chamber explosion in a direction away from the user.
The venting of the chamber explosion gases reduces the chance of the body breaking up into pieces and minimises the possibility of injury to the user. The present invention will also minimize the effect of the explosion generally and cause less damage to the gun.
In a preferred embodiment the pressure relief means comprises an area of weakness which remains intact during normal firearm operation, and ruptures in the event of a chamber explosion to vent the high pressure gases. According to an exemplary embodiment, shield means are disposed on the opposite side of the body to the pressure relief means.
Preferably, the firearm is a rifle, and most preferably the rifle is of the xe2x80x9cbull-pupxe2x80x9d type.